The two-adjacent signals causing extra traffic is something I encounter daily in Berkeley -- Ashby / Claremont & Ashby / Domingo. I probably blow an average of 5 minutes a day cause of that double intersection.

To highlight one other point from the video: You want a light to be able to clear the line built up each time. If not, flux in > flux out and that's a recipe for a growing line, which causes a traffic jam.

They are very common all down the SF Peninsula because of the Caltrain tracks. There's California/Carolan all through Burlingame (which has some of the most dangerous train crossings in the country because you can get stuck on the tracks between the lights), and then it follows El Camino on one side while the other one goes from Delaware (San Mateo) to Old County (San Mateo / Belmont / San Carlos) to Alma (Palo Alto) to Central Expressway (Mountain View / Sunnyvale).

The Old County lights at least are staggered so they are almost always green at the same time. The Central Expressway ones, not so much - there've been times I've been stuck for 20 minutes trying to cross the 100 feet from Moffett to Castro in Mountain View, because the light timing never lined up with the train signals.